1. Field of the Invention
This invention relates to screen assembly.
2. Description of Related Art
This invention has particular but not exclusive application to a security screen assembly for doors and windows of buildings including domestic residences and such like, and for illustrative purposes reference will be made to such application. However, it its to be understood that this invention could be used in other applications, such as security screens for motor vehicles including those used by police to detain persons. This invention may also be used in the construction of insect screens for doors and windows as well as screens for covering openings in drains, air conditioning vent and such like, or as a wall or petition for structures such as bus shelters and telephone boxes. The screen assembly may also be used in the construction of cages and such like which may be used to detain animals or prisoners.
Typically security screens include a frame, consisting of a plurality of frame members, and a sheet of stainless steel mesh secured to adjacent frame members by clamping members. The clamping members are usually fastened to the frame members using a plurality of threaded fasteners or rivets spaced along the length of the frame members. The fasteners are typically hidden from view by a cover strip made from a plastics material which is not very aesthetic, the cover strip being mounted on the internal face of the frame member.
Unfortunately security screens of this type described above are not always effective in preventing intruders passing through a window or door fitter with same. For example thieves who may have gained entry into the house may use a cold chisel to sever the heads of rivets used to fasten clamping members to the frame members thereby enabling thieves to dislodge the stainless steel mesh. Similarly, a screw driver may be used to unscrew the threaded fasteners used to secure the mesh to the screen.
Furthermore, the pressure applied to the fasteners to the mesh is not evenly distributed along the length of the mesh and wherein as a consequent the screens include weak spots located between adjacent fasteners.
Other screens may include gaps between the clamping members and the mesh and/or frame member which are wide enough to allow persons to insert a screw driver or such like there between so as to prise the mesh apart or dislodge the clamping members.
It is also noted that the clamping members and the frame members are usually manufactured from aluminum and wherein the fasteners are manufactured from a variety of metals including steel and brass. Contact between dissimilar metals, such as between the clamping members and the stainless steel mesh, or the brass screws and the clamping members, often leads to galvanic corrosion of at least one of the elements of the screens referred to above which in turn has a detrimental effect on the efficiency and aesthetics of same. For example, due to the corrosive effects of sea air, the fasteners often become brittle and whereby their ability to withstand blows to the stainless steel mesh is severely inhibited.
It is noted that security screens of the type described above are time consuming to manufacture.
The present invention aims to alleviate at least on of the above disadvantages and to provide a screen assembly which will be reliable and efficient in use. Other objects and advantages of this invention will hereinafter become apparent.
With the foregoing and other objects in view, this invention in one aspect resides broadly in a security screen assembly including:
a sheet of mesh like material having an edge portion;
a frame assembly including a plurality of elongate frame members which are assembled in such a manner that they define an opening which is a least partially closed by said sheet of mesh like material and wherein at least one of said frame members includes an elongate slot;
an elongate fastener closely received in said elongate slot, said elongate fastener having an elongate opening which closely received said edge portion of said mesh like material.
Preferably the edge portion extends along the entire length or width of the sheet of mesh like material and wherein the entire edge portion is retained by the elongate fastener.
Preferably, the elongate fastener is frictionally retained within the slot and wherein the fastener may be constructed from a deformable material.
In one embodiment, the fastener may be constructed from two materials. For example, the material which bears against the mesh like material may be easily deformed and may readily conform to the shape of the mesh like material. Furthermore, some of the material that bears against the mesh like material may be deformable that it may in fact penetrate the gaps between adjacent wefts or adjacent warps.
The material that bears against the frame member however may be harder than the material that bears against the mesh like material. For example, the fastener may include a hardened skin which may also be useful in guarding against penetration of a object, such as a screw driver, between the frame member and the mesh like material.
Preferably, the attachment means consists of gripping means adapted to grip opposing sides of an edge portion of the sheet of mesh like material and a recess associated with one of the frame members which is adapted to retain the gripping means. For example, in one embodiment the gripping means may be jammed into the slot which may be a recess. However, in other embodiments the gripping means may be retained within the recess by the use of suitable adhesive applied preferably to the entire length of the gripping means.
In another aspect this invention relates to a screen assembly including:
a sheet of mesh like material;
gripping means adapted to grip opposing sides of an edge portion of said sheet of mesh like material;
a frame assembly including a plurality of frame members which are assembled in such a manner that they define an opening which is at least partially closed by said sheet of a mesh like material and wherein at least one of said frame members includes retaining means having an opening which is adapted to receive said gripping means.
Preferably the retaining means is a recess and the gripping means is jammed into the recess. However it will be appreciated that in other embodiments, the gripping means may be retained within the recess by the use of a suitable adhesive or plurality of mechanical fasteners, such as screws or rivets.
In another aspect this invention relates to a screen assembly including:
a sheet of a mesh like material;
gripping means adapted to hold an edge portion of said sheet of a mesh like material:
a frame assembly including a plurality of frame members which are assembled in such a manner that they define a opening which is at partially closed by said sheet of a mesh like material, and
mounting means associated with one of said frame elements for mounting said gripping means to said frame element.
In a preferred embodiment the gripping means acts like a plug and said mounting means includes a recess which is adapted to receive said plug. Preferably the gripping means is jammed in to the recess and is retained therein.
In yet another aspect this invention relates to a screen assembly including:
a sheet of a mesh like material;
a plug like means associated with an edge portion of said sheet of mesh like material;
a frame including a plurality of frame elements which are arranged in a manner such that they define an opening which is at least partially closed by said sheet of a mesh like material, and receiving means associated with one of said frame elements which is adapted to receive and retain said plug like means.
In one embodiment the plug like means may include an edge portion of the mesh like material which has been deformed in some way so as to render it thicker than the central portion of the mesh like material. For example the mesh like material may be included folded or enlarged edge portions which may be used as a plug.
In an alternative embodiment the plug like means may consist of selected edge portions of the mesh like material which are coated with an additional layer or numerous layers of a metal or a plastics material so as to create an enlarged edge portion which may be used as a plug.
In yet another embodiment the plug like means may consist of an additional member, such as a strip of wood, metal or plastics material which is fastened to the edge portion of the mesh like material using one or more fasteners or a suitable adhesive and wherein use the additional member may be jammed into the receiving means. In some embodiments the additional member may be shaped like a wedge and may include one or more tapered side walls.
In yet another aspect this invention relates to a screen assembly including:
a sheet of a mesh like material:
a frame including a plurality of frame elements which are arranged in a manner such that they define an opening which is a least partially closed by said sheet of mesh like material;
attachment means for attaching said sheet of a mesh like material to at least one of said frame elements, the pressure applied by said attachment means to said sheet of a mesh like material being substantially even along the length of said sheet of a mesh like material.
Preferably the attachment means includes gripping means adapted to grip opposing sides of an edge portion of the sheet of mesh like material and a recess associated with one of the frame member which is adapted to retain the gripping means. For example, in one embodiment the gripping means may be jammed in to the recess. However, in other embodiments the gripping means may be retained within the recess by the use of a suitable adhesive applied preferably to the entire length of the gripping means.
In yet another aspect this invention relates to a screen assembly including:
a sheet of a mesh like material;
a frame including a plurality of frame elements which are arranged in a manner such that they define an opening which is at least partially closed by said sheet of a mesh like material;
attachment means for attaching said sheet of a mesh like material to at least one of said frame elements, and
insulation means separating said sheet of a mesh like material from said frame elements.
In a preferred embodiment the attachment means includes gripping means adapted to grip an edge portion of the mesh like material and wherein at least those portions of said gripping means which are in contact with either the mesh or the frame elements are manufactured from an insulating material such as a plastics material or rubber material.
However it will be appreciated that in other embodiments the attachment means may consist of plug like means made from an insulating material. For example, as stated previously, selected edge portions of the mesh like material may be coated with one or more layers of a plastics material so as to create an enlarged edge portion which may be jammed in a receiving means of a frame element. Alternatively an additional member manufactured from an insulated material may be secured to opposing sides of an edge portion of the mesh like material that is retained within a receiving means of a frame member.
In still yet another aspect this invention relates to a screen assembly including:
a sheet of mesh like material;
a frame including a plurality of frame elements which are arranged in a manner such that they define an opening which is at least partially closed by said sheet of a mesh like material;
attachment means for attaching said sheet of a mesh like material to at least one of said frame elements, and
filling means locatable intermediate said sheet of a mesh like material and adjacent edge portions of said frame element to which said mesh like material is attached whereby said filling means inhibits the insertion of a foreign object between said portions and said sheet of a mesh like material.
In a preferred embodiment the attachment means includes gripping means adapted to grip an edge portion of the mesh like material, said gripping means having a gripping portion which is locatable intermediate the mesh like material and the adjacent edge of the frame element which also acts as a filling means.
Alternatively the filling means may include a mouldable material which may be inserted in a recess formed in the frame elements and wherein an edge portion of the mesh like material may be immersed in the mouldable material before it has had time to set.
In yet another embodiment, the filling means may include pads/portions of a deformable material positioned intermediate the mesh and the frame elements during the assembly process.
In yet another aspect this invention relates to a screen assembly including:
a sheet of a mesh like material;
a frame including a plurality of frame elements which are arranged in a manner such that they define an opening which is at least partially closed by said sheet of a mesh like material, and
attachment means for attaching said sheet of a mesh like material to at least one of said frame elements, characterized in that said attachment means does not include fasteners which extend at least part way through said frame and said sheet of a mesh like material is not mounted on the exterior of the frame.
In a preferred embodiment the attachments means includes gripping means adapted to grip an edge portion of the mesh like material and is sandwiched between opposing portions of the frame such as a recess formed therein.
With regard to each of the various aspects of the invention referred to above, the mesh like material may be of woven or non-woven construction and manufactured from a variety of metal and/or plastics materials. Depending upon the intended purpose of the screen, the mesh may be rigid, semi-rigid or a flexible mesh. For example, insect screen assemblies may include a flexible mesh manufactured from a plastics material.
Security screens, drains and screens mounted over openings in vents such like typically include a rigid mesh. Accordingly, in some applications the mesh like material may be manufactured from extruded fibres composed of synthetic long chain polymides which are very strong and are often referred to by the trade name xe2x80x9ckevlarxe2x80x9d. Alternatively, the mesh like material may be manufactured from aluminum, brass, steel, stainless steel or numerous other metal alloys. The mesh like material may be of a woven or non-woven construction and the case of security screens, while primarily intended to resist attack by would be intruders, the mesh like material may also be adapted to inhibit the passage therethrough of selected insects and/or other pests such as mice and snakes. For example, the mesh like material may include a plurality of wires woven together in a manner whereby the spacing between adjacent warps is not greater than 2.2 mm and the spacing between adjacent warps is no greater than 2.2 mm. Alternatively the mesh like material may be an expanded mesh.
The gripping means referred to above may consist of two opposing gripping members linked by connecting means.
The connecting means may consist of an intermediate web portion linking the two gripping members. Alternatively, the connecting means may include a fastener, such as rivet or a screw, used to secure one gripping member to the other.
The gripping members may be adapted to cover or envelop an edge portion of the mesh like material, the gripping means being manufactured from a plastics material such as nylon or PVC. The external walls of the gripping means may be adapted to engage abutting portions of the retaining means. For example the external walls may be tapered and/or may include ribs, barbs or other surface irregularities.
The gripping members may be constructed from a variety of materials including various metals and plastics materials. The construction of the gripping members may be substantially homogeneous.
Alternatively, the gripping means may be constructed from two or more different materials.
For example, the gripping members may have a laminar construction and wherein the portion of each gripping member that bears against the mesh like material may be more easily deformed and hence more inclined to conform to the shape of the mesh like material than the portion of the gripping member that bears against the surfaces of the retaining means.
The retaining means may include a channel shaped recess extending at lest part way along the length of the frame element or frame member. For example, the frame member may be constructed from an extruded section and wherein the extrusion may include a recess formed therein which is adapted to receive an edge portion of the mesh like material and any gripping means that may be attached thereto. Alternatively a separate member having a recess formed therein which is adapted to receive an edge portion of the mesh like material and any gripping means attached thereto may be secured to the frame element or frame member.